In the manufacture of vehicle carburetors it is essential that they be adjusted and calibrated so as to function efficiently under widely differing atmospheric conditions. For example, a vehicle's carburetor must be capable of functioning properly at high altitude, such as in mountainous areas, and it also must be capable of functioning substantially equally well at sea level and lower altitudes. Each carburetor, therefore, must be subjected to calibration procedures under conditions simulating quite accurately the various atmospheric conditions, i.e., barometric, humidty, and temperature, that are likely to be encountered in use.
Various carburetor calibration systems have been proposed heretofore, examples of which are disclosed in U.S. Pat. Nos. 3,928,080; 3,851,523; 3,975,953; 3,517,552; and 3,524,344.
If a carburetor is to be tested under conditions simulating barometric pressures higher than the ambient pressure, the air utilized in the testing must be compressed. Compression of air, however, customarily is accompanied by a substantial increase in its temperature. It is extremely rare that the temperature of compressed air corresponds to the temperature at which a carburetor is to be tested, so it is conventional to pass the compressed air through refrigeration apparatus for the purpose of cooling the air. The cooling process for the compressed air, however, conventionally requires substantially large refrigeration apparatus because of the generation of heat due to compression, thereby resulting in excessive energy consumption. The air subsequently is heated and moisturized as required to simulate desired atmospheric conditions.
A principal object of the invention is to provide a system for simulating different atmospheric conditions and which minimizes considerably the complexity and energy requirements of previously known systems for similar purposes.